Andi

I dyno'd my Viper last night. 439rhwp, right around the # I expected. Funny how it's advertised 5hp higher than the Z06 yet it dyno'd lower than both my Z06's. But then I know I was buying a slower car, I just wanted one with good brakes, a little different styling, and a non-removable roof.....

Here's my stock Viper SRT10 coupe dyno at ~350 miles:



I'll be honest with you, the curve surprised the hell out of me. Maybe it's just the level of grip, or the weight and the 3.07 rear end ratio, but this whole time, I thought the thing had no low end. It never spins the tires. It just goes. Maybe these Pilot Sports will actually live longer than those Eagle F1 Supercars that had pencil eraser-like longevity. The other thing that surprised me is how the horsepower curve never drops at all even before redline. I did a shift point analysyis and each shift point drops you to ~4000-4600 from redline -- still a drop in power even from the highest shift point possible. So my previous perception -- that you want to short shift the snake, was totally incorrect. This thing begs to be revved. It just doesn't *feel* like it does.

OK, back on topic. Z06 vs. Viper. The Viper feels slower. A good bit slower. At least compared to the first time you floor the Z06 when you're getting full power, before the Z06's timing retard and the massive HP loss. (BTW, we did 3 pulls on the Viper in 10 minutes and they were all within 1hp of each other).

So, I decided to plot horsepower vs. engine speed since the Viper and Z06 have identical top speeds in 4th gear, which negates the redline and gearing differences. Plotting HP vs. engine speed also has one other beautiful property: at any given speed, actual rear wheel torque (post drivetrain multiplication), i.e. *thrust*, is directly proportional to horsepower. So, forward thrust in each car is represented by the HP curve in the below curves.

There are three curves: My first Z06 (now owned by Jim Hall) which made 449rwhp (red curve). This is an average Z06 dyno, and his motor is still running strong. Then there's my second Z06, which made 468rwhp (green curve). That motor lasted 5,300 miles before it spun a rod bearing. And then there's the Viper curve (the blue curve).



As you can see the Viper bisects the average Z and the 5,300 mile one-hit-wonder in the low-midrange, before getting passed by even the average Z up top.

I think it'd be a close race if the Z06 had a passenger and the Viper didn't. It's a 300lb weight difference, plus a ~10rwhp average rwhp difference in the Z06's favor. But, as it sits, the sits, the Z06 is the faster car. As much as I'd love it if it did, torque doesn't win races.



Andi

outnumbered

Nice info Andi. My 04 Viper dynoed at 440 and 469. The #'s are very consistent. The only other thing I see is the 3:07 rear vs the 3:42 rear.The gear difference would perk the Viper up a little in the bottom.

Your comments all seam to be fair. I have always noticed the Z a touch quicker from the start. At cruising speeds the pull feels about the same.

Both a blast to drive.

QUIKAG

Blue curve is the Viper, not the red curve, Andi.

Great info, nevertheless!

Andi

Thanks, I redid the graphs for clarity and didn't realize the colors got switched around.

QUIKAG

Get your butt over to my house. I want to see the black snake in the daytime! I couldn't see it very well the other night with those flashing blue and red lights behind us.

VicCaerter

you can't forget about aerodynamics either... I can't imagine the snake is sleaker than the Z. good stuff there!

outnumbered

Must not be too bad. Top speed is 197 drag limited.The Z is 198 drag limited.

Andi

"A low front air dam, a flat bottom, and an undertail diffuser act in concert with the Viper's sleek silhouette and subtle integral tail spoiler to keep the plot on the ground at speeds up to its claimed 190-mph top speed."

Andi

Viper specs

Viper Drag: Drag area, Cd (0.39) x frontal area (19.3 sq ft): 7.5 sq ft

Z06 specs

Z06 Drag: Drag area, Cd (0.34) x frontal area (22.3 sq ft): 7.6 sq ft

-----------
Aero: it's a wash....

Mr. Lucky

Great post! Are those regular Pilot Sports or PS2's?


Actually, I think the Viper's 3.07 would have the opposite effect.

-Bob

outnumbered

The Viper has a 3.07 ratio. Are you saying if you go to a 3.42 like the Corvette the Viper would be less quicker than it now is?

raj

Good comparisons! The beauty of the Z06's higher revving powertrain is that it essentially widens the powerband. The redline (7K vs. 6K) difference translates to a 16.7% increase in available bandwidth while the gearing difference (3.42 vs. 3.07) is only 11.4%. Basically, the Z06 can support an even shorter rear axle ratio (3.58:1, if available) which will enhance acceleration further (assuming traction is not an issue, of course) while still maintaining equivalent top speeds as the Viper in every gear!

Mr. Lucky

It's not a big deal, but I understood you to say that the 3.07 gearing in the Viper made it "perkier" in the bottom end, which I interpreted to mean as "quicker." Clearly (all other things being equal), the 3.42 would be quicker off the line, not the 3.07.

I think we mean the same thing but are just saying it differently.

outnumbered

I guess I should have been more clear.

It's funny. There is a thread on the Viper site vs Z06. Someone thought a shifter change would get them closer to the Z06 in 1/4 mile.They obviously don't like being 2nd.

Lankhoss

I read somewhere that there is more parasitic loss in the Viper's drivetrain than the Z06, and that the motors probably put out almost identical power. Not sure how true this is, or not.

I have noticed that Vipers seem more "peppy" down low, but don't have much experience with them. I have raced a few, and they always had an advantage from a dig or very slow speeds, and I rode in an SRT-10, that seemed a bit more strong at low RPM's than mine.

Great post!

RadioManJ350Z33

I had a 4:30 SVO gear in my 97' COBRA... just thought I'd share.

Andi

Regular wheel-hoppy Pilot Sport 1's in the run-flat variety.

Andi

dave07z

Light to light my Z feels like it will dust my Viper(both 06'). That said the Vipers power comes on when you really nail it, as you once pointed out. It's also a totally different feel. Gearing is def. part of that different feel. I've only had the Viper for approx. 3 weeks now. Still getting used to it. No matter what any haters say, the Viper is an awsome american muscle car, and a total blast to drive.

Mr. Lucky

I'm glad you added that adjective.

Gawd, I wish the PS2's came in a wider size selection for 19s. For street tires they are awesome.

Lankhoss

I just ordered the 345/30/19's that are PS2's???